Furnace header



Patented Sept. 8, 1936 PATENT OFFICE FURNACE HEADER George P. Jackson,Flusling, N. Y., assignor to Combustion Engineering Company, Inc., New

York, N. Y.

Application October 9, 1934, Serial No. '747,514

5 Claims.

I My invention pertains primarily to headers and is particularlyapplicable to headers of water cooled tubes for the Walls of boilerfurnaces.

I It has become common practice to provide the inner surfaces offurnaces such as those used with boilers or like structures with rows ofvertical Water tubes 'the lower ends of which connect to headers forsupplying Water to such tubes. It has been found necessary to pro-videas many hand-bole openings in the lower header as there are verticalgenerating tubes. Except for troubles due to action of hot gases onhand-hole closures, the most convenient and economical arrangement ofsuch tubes and lower headers is to place. such headers alongvthe innerfaces of the wall or walls of .the furnaces, but the requirement ofhand-holes has resulted in placing the headers entirely away from hotgases either by extending the wall' tubes downward to throw the lowerheaders entirely out of the zone of hot gases or by bending the lowerends of the tubes to cause them to run through the outer refractory Wallof the furnace. The latter arrangement is usually the. most economicaland. almost all the recent installations have placed the headers for thelower tubes on the outside of the furnace walls altho such location ofthe headers involves bending of the wall tubes outwardly through therefractory Section of the wall as' well as a special and costly sealagainst air leaks where the tubes pass through the refractory sectionand insulation of the exposed tubes and headers to prevent loss of heat.

v It is an object of my invention to provide an arrangement having theheaders on the inside of the refractory Wall section and which shall befree from the above mentioned hand-hole diiculties.

In .carrying out my invention, the wall tubes are run vertically intothe upper sides of the headers without bends and the hand-holes andclosures therefor are located on the lower surfaces of the headers whilesuch closures are protected by suitable means from the furnace gases sothat distortion and/or freezing of the parts as well as spalling of suchremovable bricks asmay be used is avolded.

The novel features of my invention are pointed out in the appendedclaims. The invention itself, however, together with its objects andadvantages, Will best be understood from the following description of aspecific form thereof illustrated in the accompanying drawing andselected as an exemplification of the invention from a number ofpossible embodiments thereof. In thedrawing,

Fig. 1 is a sectional elevation of a portion of a furnace chamber havingwater cooled wall tubes and header arrangement in accordance with myinvention.

Fig. 2 is a fragmentary View on an enlarged 5 scale of a portion of Fig.1.

In the arrangement illustrated, a refractory section of a wall of thefurnace chamber IU is 'shown at IZ. Furnace IO is assumed to beassociated With a steam boiler but the invention is not limited toboiler furnaces. Along the inner face of Wall section |2 is a row ofvertical water cooled tubes one of which appears at !4. The lower end ofeach of tubes 14 is rolled into the upper face of a header !6, the topconnections for 15 tubes M being immaterial to the invention and notbeing illustrated, Header !6 lieson the inside of the refractory wallsection !2 in such position that it is subject to hot furnace gasesexcept where some provision may be made to protect it from such gases. i

In the lower face of header IS, handhole openings !8 are provided, onefor each tube !4 to permit access to the lower ends of such tubes.During operation, the openings !8 must be closed and closure means 20are shown for this purpose. `A novel type of hand-hole closure meansisillustrated and described in detail hereinbelcw, but I do not limitmyself to such type of closure. In order to: protect, at least in part,the closure means 20 from the hot gases, the refractory of wall 20 isbuilt out into a shoulder 22 below header IS. However, the fixedshoulder proper cannot be brought close to the bottom of header ISwithout cutting ofi access to the closure means gr 20. I therefore buildup the shoulder 22 as close as practicable to the bottom of header [6 byremovable bricks 24, thereby providing ready access to closure means 20and at the same time shielding such means considerably from the hotfurnace gases. However, the ordinary hand-hole closure projectsoutwardly from the header and so does not permit the bricks to bebrought very close to the lower face of the header and, even if theclosure means should not project outwardly from the face of the header,it is difiicult to arrange the bricks so close to the header face as toprevent serious trouble from the action of the gases on both the closuremeans and the top face of the bricks 24 unless special means are pro- 5vided to seal the space between the header and such bricks on thefurnace side of the closure means or near the outer edge of the bricks.It should be explained that while refractory brick such as shown at 24are quite capable of Withstanding high temperatures when heated on oneface only, they deteriorate due to spalling caused by unequal expansionand contraction when heated on two adjacent faces.

In the embodiment of the invention illustrated in the drawing, the space26 between the header !6 and the bricks 24 is closed along the furnaceend of such space by a metal fin 28 which is fixed to the header !6 atthe upper end of such fin by a heat conducting joint, weld metal 38(Fig. 2) between the fin and the header being illustrated for thispurpose. As shown, the fin 28 abuts the Vertical furnace face of bricks24 so as to form r an efiective seal therewith to substantially excludefurnace gases from space 26. Moreover, a fin permits relative movementbetween header IE and bricks 24 without impairment of its sealingaction. such movement necessarly occurs due to changes in temperature oftubes [4. However, I do not limit myself in all cases to a fin for suchsealing purpose.

The shorter the space 28' in the vertical direction, the thinner the fin28. may be without danger of its burning off, because a narrower finneed conductless heat to the header IE. I have accordingly, devised andillustrated a novel handhole closure illustrated in the drawing whichhas the valuable characteristic of permitting a Very considerablereduction in the height of space 26.

As shown and particularly illustrated in Fig. 2, my handhole closure hasan internal cup shaped closure plate 32 adapted'toseat against the innerface of the header Hi to close the opening |8 in the usual manner.Usually a gasket 34 will be employed between the plate 32 and the headerIS altho the gask-et is no part of the present invention. Plate 32 has abolt 36 riveted on in the usual manner, bolt 36, however, being muchshorter than usual so as not to project beyond the'opening !8. The yok-emember 38 also is unusual and arranged so as not to project beyond theopening !8. In order to permit the yoke 38 to sustain a tension in thebolt 36 to hold plate 32 in place, the outer edge of the opening !8 isbeveled as indicated at 48 and the yoke 38 has a slope corresponding tothe bevel of the header at point 40 so that yoke 38 seats against theheader around the opening [8. A nut 42 is employed on the bolt 36 in theusual manner in order to clamp the plate 32 and the yoke 38 together tohold the plate 32 firmly in place. It will be seen that the handholeclosure in accordance with my invention can be designed to lie entirelywithin the spac-e outlined by the header 16, but I do not limit myselfto this in all cases.

While the'hand-hole closure illustrated in the drawing is particularlywell adapted for use with headers subject to hot gases, otherapplications may be made of it and I do not limit myself to anyparticular header location of arrangement so far as my claims to theclosure means proper are concerned.

In Fig. 1, means are shown for supplying headers [6 with water, suchmeans including a number of pipes entering the side of the header, onesuch pipe being shown at 44. However, I do not limit myself to anyparticular arrangement for supplying header |6 with water. In Fig. 1,moreoVer, are illustrated several tubes 46, 46 arranged so as to form ascreen across the furnace chamber 10 at a level somewhat above that ofheader Hi so that the portion 48 of chamber o lying below the tubes 46may be considered as an ash pit. It Will be understood, therefore, thatthe phrase "furnace chamber" as used in the appended claims covers anash pit portion of a furnace as well as the combustion zone proper.

What I claim is:

I. The combination of a furnace chamber, a header within said chamberarranged. along the wall thereof and having a hand-bole in its lowerface, clcsure means for said hole, refractory directly below and spacedfrom said header, and a fin fixed to said header in heat conductingrela.- tion thereto on the furnace side of said hole and extendingdownwardly to overlap said refractory and to substantially excludefurnace gases from the space between said header and refractory.

2. The combination as set. forth in claim 1 and in which the refractoryfacing the hand-hole is readily removable to permit access to such hole.

3. The combination of a furnace chamber, a header within said chamberhaving a hand-hola in its lower face, means for closing said hole andlying substantially within the outer surface of said header, removablerefractory immediately below and spaced from said header and means forsubstantially excluding furnace gases from the space between saidreiractory and header.

4. The combination as set forth in claim 3 and in which the gasexcluding means includes a metal fin fixed to said header in heatconducting relation thereto.

5. The combination of a furnace chamber, a header within said chamberarranged along the wall thereof and having a hand-hole` in its lowerface, closure means for said hole, ref'actory below said header andforming a shoulder spaced from the latter, and means in heat conductingrelation with said header for scaling the space between the latter andsaid shoulder to prevent contact of hot gases With the upper face ofsaid shoulder and the opposed lower face of said header, the refractorydirectly below said header being readily removable for providing accessto said hand-hale.

GEORGE P. JACKSON

